In recent years, in solid-state imaging devices such as CCD (Charge Coupled Device) image sensors and CMOS (Complementary Metal Oxide Semiconductor) image sensors, reduction in pixel size has accelerated. The reduction in pixel size reduces the number of photons entering a unit pixel, which results in reduction in sensitivity and reduction in S/N ratio. Moreover, in a case where a color filter including a two-dimensional array of primary-color filters of red, green, and blue is used for colorization, in a red pixel, green light and blue light are absorbed by the color filter, which causes reduction in sensitivity. Further, in order to generate each color signal, interpolation of pixels is performed, which causes so-called false color.
Accordingly, for example, PTL 1 discloses an image sensor using an organic photoelectric conversion film having a multilayer configuration in which an organic photoelectric conversion film having sensitivity to blue light (B), an organic photoelectric conversion film having sensitivity to green light (G), and an organic photoelectric conversion film having sensitivity to red light (R) are stacked in order. In the image sensor, signals of B, G, and R are separately extracted from one pixel to achieve an improvement in sensitivity. PTL 2 discloses an imaging element in which an organic photoelectric conversion film configured of a single layer is formed, and a signal of one color is extracted from the organic photoelectric conversion film and signals of two colors are extracted by silicon (Si) bulk spectroscopy.